"It's like talking to a brick wall" and "We'll have to agree to disagree" are popular sayings referring to the frustrating experience of discussing issues with people who seem to be beyond the reach of argument. It's often claimed that some people - fundamentalists or fanatics - are indeed sealed off from rational criticism. And every month new pop psychology books appear, describing the dumb ways ordinary people make decisions, as revealed by psychological experiments. The conclusion is that all or most people are fundamentally irrational. Ray Scott Percival sets out to demolish the whole notion of the closed mind and of human irrationality. A key aspect of Percival's approach is to identify "the persuader's predicament", the situational logic of the propagandist. Percival contends that a propagandist is faced with a trade-off between his message being closed to criticism and the message reaching and converting as many people as possible. It is possible to make a belief system more closed to criticism, but only by limiting the wide dissemination of the system. Percival illustrates the way belief systems adapt to criticism by an examination of two ideologies, Marxism and Freudianism, and by various examples drawn from the history of religion.

The book is published by Open Court.